Fusible link for fire sprinklers

ABSTRACT

A fusible link holds levers positioning a cap on an orifice in a fire sprinkler and is so formed that upon fusing the separation of the parts of the fusible link insures the freeing of the levers and the opening of the sprinkler.

[ Feb. 18, 1975 United States Patent [191 Good'sell, Jr. et al.

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Pr m l m E a RSk mo F M m m md n K h m m m m ETb m mm UV F..m 4 M UAssistant ExaminerMichael Mar Attorney, Agent, or Firm-Webster B.Harpman ABSTRACT [21] Appl. No.: 478,155

A fusible link holds levers positioning a cap on an orifice in a firesprinkler and is so formed that upon fus- 22 41 97 63 n. 6 BA 9. 6" uSnt Um NH 55 [58] Field of Search.............. 169/37, 38, 40, 42, 39

References Cited UNITED STATES PATENTS ing the separation of the partsof the fusible link insures the freeing of the levers and the opening ofthe sprinkler.

1,209,574 169/42 6 Claims, 7 Drawing Figures PATENT FEB 1 8 ms SHEET 2OF 2 FIG.3

1 FUSIBLE LINK FOR FIRE SPRINKLERS BACKGROUND OF THE INVENTION 1. Fieldof the Invention This invention relates to fusible links as employed insprinklers in fire extinguishing sprinkler systems.

2. Description of the Prior Art Prior structures of this type havegenerally employed two pieces of metal soldered to one another, each ofwhich is provided with an opening and the openings arranged in spacedrelation so as to receive projecting levers of the sprinkler. See forexample U.S. Pat. Nos. 1,317,629, 1,145,883 and 3,061,016.

This invention provides a compact fusible link with a common centeropening and a configuration insuring a desirable separation upon fusingof the fusible material of the link.

SUMMARY OF THE INVENTION A fusible link for a sprinkler in a fireextinguishing sprinkler system is disclosed which is formed of a pair ofmetal discs, each of which are provided with oppositely disposed slotsand registering raised areas. The

inner ends of each of the oppositely disposed slots register to form acentral opening in the discs when the same are assembled and soldered toone another. Cold flow of the fusible link is avoided by the mechanicalinter-engagement of the raised areas which are so formed as to requirethe physical separation of the metal discs when the fusible link reachesfusing temperature and thereby insures the positive separation of thelink and the freedom of the levers which control the sprinkler.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical section through asprinkler showing the fusible link in lever retaining position.

FIG. 2 is a section similar to FIG. 1 showing the fusible linkimmediately following fusion therein.

FIG. 3 is a perspective view of a sprinkler with parts broken away andparts in cross section showing the fusible link completely separatedpermitting operation of the sprinkler.

FIG. 4 is an exploded top plan view showing the two metaldiscs of thefusible link.

FIG. 5 is an enlarged top plan view of one of the discs seen in FIG. 4.

FIG. 6 is a section on line 66 of FIG. 5, and

FIG. 7 is an exploded top plan view of a pair of metal discs of modifiedform of fusible link.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the form of the inventionchosen for illustration and description herein the fusible linkcomprises a pair of identical metal discs 10 each of which has a slot 11extending into the body of the disc to a point past the center thereofand each of which has a pair of rounded raised areas 12 formed thereintogether with a plurality of flat raised sections 13.

Two of the metal discs 10 are assembled in superimposed relation as seenin FIG. 1 of the drawings with one set of the flat raised sections 13slightly spacing the discs to permit the same to be readily soldered toone another with a suitable fusible solder. In assembled and soldedrelation as seen in FIG. 1 of the drawings, the rounded raised areas 12nest one within the other and prevent the discs 10 from being movedsidewardly relative to one another until and unless the solder holdingthe same in face to face engagement fuses as will be understood by thoseskilled in the art.

At such time as the solder fuses the discs 10 must move apart from oneanother as they attempt to slide with respect to one another and asillustrated in FIG. 2 of those drawings. Those skilled in the art willobserve that when the fusible link described herein is installed in asprinkler such as seen in FIGS. 1, 2 and 3 of the drawings, thedischarge orifice of the sprinkler is closed with a cap 14 and held inclosed position by a pair of levers 15 and 16 portions of the levers l5and 16 being positioned through the center opening in the fusible linkas formed by the registering inner ends of the slots 11 therein as seenin FIG. 1 of the drawings. The sprinkler in which the fusible link ofthe invention is seen installed in FIG. 1 of the drawing includes athreaded base 17, a frame 18 and a deflector 19 all as in a conventionalsprinkler and the cap 14 closes the discharge orifice which extendsvertically through the base 17 as will be understood by those skilled inthe art.

By referring now to FIG. 3 of the drawings, the complete separation ofthe discs 10 of the fusible link may be seen and it will be observedthat one end of the lever 16 is still engaged in the innermost end ofthe slot 11 in one of the discs and that the tension and resilience ofthe levers 15 and 16 of the sprinkler has resulted in the parts of thefusible link and the levers moving clear of the center axial portion ofthe sprinkler to insure the release of the cap 14 and the opening of thesprinkler to permit the flow of fire extinguishing fluid therethrough.

By referring now to FIGS. 5 and 6 of the drawings, greatly enlargeddetailed views of one of the discs 10 may be seen and it will beobserved in FIG. 6 in particular that the flat raised sections 13 arevery small in relation to the dimensions of the round raised areas 12.The flat raised sections 13 are preferably formed in the metal of thediscs 10 by making dies having the appropriate configurations therein toboth punch out slots 11, form the round raised areas 112 and create theflat raised sections 13 simultaneously as willoccur to those skilled inthe art. The preferred shape of the round raised areas 12 is almost ahalf sphere as may be seen in FIG. 6 of the drawings, and the radius ofthe inner surface of the round raised areas 12 is the same as the radiusof the exterior surface thereof so that the same will nest one withinthe other as hereinbefore described. This results in a thinning of themetal at the edges of the round raised areas 12 as compared with thethickness of the metal in their outermost portions.

Modifications in the structure of the fusible link disclosed herein maybe made without departing from the advantages of the same and one suchmodification is illustrated in FIG. 7 of the drawings wherein the lengthof the slot has been shortened and round apertures formed in oppositelydisposed relation thereto. In FIG. 7 a pair of discs 20 are eachprovided with a pair of round raised areas 21 and a plurality of flatraised sections 22 and each of the discs 20 has a short slot 23 with arounded inner end 24. Aperture-s 25 are formed in the discs 20 inoppositely disposed relation to the slots 23 and so positioned that whenthe: pair of discs 20 are placed in superimposed relation and solderedto one another, the resulting composite fusible link has a pair ofspaced openings therethrough, each of the openings being defined by oneof the apertures 25 and the inner end of the slots 24 in the adjacentdisc. The modification of FIG. 7 can therefore be used with sprinklershaving levers projecting to one side of the frame and wherein the endsof the levers are spaced vertically with respect to one another and arethus capable of being received by the dual apertures in the modifiedform of the fusible link. In operation the fusible link of themodification operates in the same manner as the fusible link of thepreferred form of the invention hereinbefore described.

It will thus be seen that a fusible link for a fire sprinkler has beendisclosed which may be quickly and inexpensively formed and assembledfrom two shaped metal discs and that it provides a central aperture forthe reception of levers in a sprinkler, at least one of which ispositioned on the axial center line of the discharge orifice of thesprinkler.

Although but two embodiments of the present invention have beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention.

We claim:

1. A fusible link comprising a pair of metal members positioned insuperimposed relation and soldered to one another, each of the metalmembers having projecting registering configurations arranged to preventthe metal members from sliding sidewardly with respect to one anotherand each of the metal members having a slot formed therein from one sidethereof, the respective positioning of the metal members being reversedin assembly so that the slot in one of said members extends to one sideand the slot in the other of the metal members extends toward theopposite side of the fusible link and so that the inner ends of theslots register and form an opening through said metal members.

2. The fusible link of claim 1 and wherein said metal members are roundand the opening therethrough is in the center thereof.

3. The fusible link of claim 1 and wherein said configurations arerounded raised shapes.

4. The fusible link of claim 1 and wherein said configurations arerounded raised shapes and wherein the inner and outer surfaces thereofare of the same radius.

5. The fusible link of claim 1 and wherein raised sections are formed onsaid members and arranged to closely space the same and provide spacefor solder.

6. The combination of a sprinkler having a discharge orifice on theaxial center line thereof and a frame thereover and levers holding a capon said orifice, at least one of said levers disposed between said frameand cap on said axial center line and a fusible link consisting of twometal members soldered to one another in superimposed relation, each ofthe metal members having projecting registering configurations and aslot inwardly from one side thereof extending beyond the center thereof,the slots being in oppositely disposed relation in said link with theinner ends thereof in registry and forming an opening on said axialcenter line, said levers having portions positioned in said opening soas to be restrained by said fusible link.

1. A fusible link comprising a pair of metal members positioned in superimposed relation and soldered to one another, each of the metal members having projecting registering configurations arranged to prevent the metal members from sliding sidewardly with respect to one another and each of the metal members having a slot formed therein from one side thereof, the respective positioning of the metal members being reversed in assembly so that the slot in one of said members extends to one side and the slot in the other of the metal members extends toward the opposite side of the fusible link and so that the inner ends of the slots register and form an opening through said metal members.
 2. The fusible link of claim 1 and wherein said metal members are round and the opening therethrough is in the center thereof.
 3. The fusible link of claim 1 and wherein said configurations are rounded raised shapes.
 4. The fusible link of claim 1 and wherein said configurations are rounded raised shapes and wherein the inner and outer surfaces thereof are of the same radius.
 5. The fusible link of claim 1 and wherein raised sections are formed on said members and arranged to closely space the same and provide space for solder.
 6. The combination of a sprinkler having a discharge orifice on the axial center line thereof and a frame thereover and levers holding a cap on said orifice, at least one of said levers disposed between said frame and cap on said axial center line and a fusible link consisting of two metal members soldered to one another in superimposed relation, each of the metal members having projecting registering configurations and a slot inwardly from one side thereof extending beyond the center thereof, the slots being in oppositely disposed relation in said link with the inner ends thereof in registry and forming an opening on said axial center line, said levers having portions positioned in said opening so as to be restrained by said fusible link. 